Refrigeration system



,sure responsive vessel containing the refrigerant.

REFRIGERATION SYSTEM George B. Murphy, Carle Place, N.Y.

Application December 1, 1958, Serial No. 777,311

10 Claims. (Cl. 62-174) This invention relates to mechanicalrefrigeration apparatus and a method in which the various phases of therefrigeration cycle take place in one device.

In the usual vapor compression type of refrigeration apparatus, therefrigerant is caused to circulate progressively from an uppertemperature and pressure region of the cycle to a lower temperature andpressure region thereof through various segregated and distinct devicesto accomplish the expansion of the condensed refrigerant.

It is the principal object of this invention to provide a method andapparatus in the form of mechanical refrigeration in which the variousphases of the refrigeration cycle take place in one device.

It is a further object of the instant invention to provide arefrigeration tank in which there is suspended a completely enclosedexpandable and contractable vessel containing a suitable refrigerantmaterial adapted to be liquefied upon the application of high pressureand below a certain temperature. During one phase of the cycle ofoperation, a convective energy carrier in the form of a flowable fluidis circulated through the refrigeration tank by a pump whereby heat istransferred from the refrigerant to the flowable fluid as the lattercompresses the contractable vessel containing the refrigerant. Duringthe next phase of operation, some of the flowable fluid is pumped fromthe tank into a reservoir. As this action empties the tank, therefrigerant vessel expands, which expansion lowers the temperature ofthe convective carrier fluid remaining in the tank; during the nextphase of operation, the refrigeration tank is interconnected with theregion to be cooled. The convective fluid remaining in the refrigerationtank is then allowed to circulate through the region to be cooledwherein the circulating fluid is at a lower temperature by reason ofexpansion of the refrigerant vessel containing the refrigerant gas.

It is a further object of the invention to employ an expandable andcontractable but fully enclosed and pres- The refrigerant is maintainedenclosed in the vessel for the entire cycle of operation. This providesthe advantage of avoiding loss of refrigerant which loss is otherwiseexperienced while such refrigerant is circulated as in prior artsystems, and provides the further advantage of eliminating theprecautions observed in prior art refrigerant circulating systems forpreventing leakage, particularly, where a dangerous refrigerant isemployed. Consequently, any suitable refrigerant may be employed in thepractice of the invention.

It is a further object of the invention wherein it allows the use of anysuitable flowable convective carrier, such as water, brine'or otherflowable material in the practice of the invention.

Further objects and advantages will become apparent from the followingdescription of the invention taken in conjunction with the figures, inwhich:

Figs. 1 through3 illustrate schematically the various States Patent iPatented Dec. 1, 1959 ICC phases of the cycle of operation in accordancewith the practice of the instant invention.

Reference is now made to the figures wherein 10 depicts a rigid pressuretype tank containing an expandable and contractable vessel 11 ofsuitable material. Vessel 11 is fully enclosed and is immersed andsupported within a fluid 12. Fluid 12 is a flowable convective energycarrier of any suitable material. Vessel 11 contains an expandable andcontractable refrigerant material 9 such as a suitable gas which uponcontraction, by reason of pressure applied to the outer surfaceof'vessel 11, will convert at some predetermined pressure andtemperature into a liquefied state. Tank 10 has a port 13 coupled toareversible pump 14. Pump 14 is coupled to a twoway Valve 15. Pump 14 isoperated by a reversible motor M. Motor M and valve 15 are regulated byrespective control circuits to be described hereinafter. Depending uponits position, valve 15 is adapted to interconnect tank 10 alternatelywith one or the other of two conduits 16 and '17. Conduit 16 has onebranch leading to a fluid supply or reservoir 23 and a return branch 18connected to a tank outlet port 19 via a regulating valve 20 and a checkvalve 27. Check valve 27 will permit fluid to flow from tank '10 in thedirection of arrow 27a when branch 18 is opened by regulating valve 20in response to a predetermined high pressure in tank 10. Conduit 17passes through a region 21 to be cooled and returns to tank 10 via aport 22.

The cycle of operation will be described starting with the condensing orcompression phase thereof. It will be understood that reservoir 23 issubstantially full with fluid 12 and that there is a substantialpressure head existing in space 24 between the surface level of fluid 12and the ceiling of reservoir 23 at the start of the condensing phase. Inaddition, conduit 16 and branch 18 are substantially full with fluid 12,regulating valve 20 is closed to prevent porting of fluid 12 out of tank10, vessel 11 is substantially fully expanded and valve 15 is orientedas shown in Fig. 1 at the start of the condensing phase. With valve 15turned as shown in Fig. 1, reservoir 23 is interconnected with tank 10;whereas motor M has been adapted to pump fluid 12 in the direction ofarrow 25a.

Fluid 12 is pumped from reservoir 23 through conduit 16 in the directionof arrow 25b and into tank 10 via port 13 and consequently builds uppressure in tank 10 acting upon vessel 11. The flow of fluid 12 intotank 10 is also aided by the pressure head previously developed atregion 24 in reservoir 23. The foregoing action contracts vessel 11 andthus compresses the refrigerant gas 9 in said vessel. Compression of gas9 in vessel 11 results in generation of heat which is transmitted tofluid 12 in tank 10. The pressure build up in tank 10 will increaseuntil regulating valve 20 opens at a predetermined pressure to permitflow of some fluid 12 through the low pressure side of the system andthus through check valve 27, branch 18, conduit 16 and back into tank 10in the direction of arrows 27a and 25a. Accordingly, upon opening ofregulating valve 20, fluid 12 circulates about the system via branch 18.The amount of flow of fluid 12 from tank 10 via outlet port 19 is lessthan the amount of fluid flow into tank 10 via port 13. The differentialin quantity of fluid 12 is supplied from reservoir 23 which is graduallydepleted. The foregoing action increases the pressure build up in tank'10 and thus further contracts vessel 11 and is obtained by continuedoperation of pump 14. Compression of gas 9 in vessel 11 results in ageneration of heat which is transmitted to the circulating fluid 12. Asfluid 12 circulates, it is cooled by cooling means such as a fan 28. Fan28 is also adjusted to cool the contents of reservoir 23. Continuedapplication of pressure by pump 14 and cooling by fan 28 results in gas9 converting into a liquid state at a predetermined pressure andtemperature. Even though a state of relatively constant pressure is nowreached in tank 10, circulation of fluid 12 around tank 10 and branch 18is continued by pump 14 until the system is triggered or commanded tostart the expansion phase of the cycle. Fig. 1 depicts vessel 1-1 in itscontracted state.

When the temperature in region 21 finally rises above a predeterminedvalue, for example 50 F., a thermostat 29 responsive to the temperaturetherein will operate to change direction of motor rotation and thus thedirection of pump operation to etfectflow of fluid 12 in the directionof arrow 25d. Activation of thermostat 29 at such preselected andrelatively high temperature in area 21 initiates the expansion phase ofthe cycle of operation which is depicted in Fig. 2. During this phase ofoperation, fluid 12 is pumped quickly from tank 10 via port 13 andconduit 16 in the direction of arrow 25c (Fig. 2) back into reservoir23. Pumping action is aided by the high pressure existing in tank 10 andthe low pressure existing in reservoir 23. Check valve 27 prevents flowof fluid 12 against arrow 27a and into tank 10; As fluid 12 returns toreservoir 23, a pressure head is developed at 24 to be used as an aidein emptying reservoir 23 during the first phase of cycle of operation asnoted hereinbefore. Vessel 11 upon emptying of tank It? now expands,which expansion causes transfer of heat from fluid 12 remaining in tank10 to refrigerant 9 in the expanding vessel 11. The refrigerantultimately reconverts to a gaseous state.

The temperature of fluid 12 remaining in tank continues to cool byreason of the foregoing action. The drop in fluid temperature in tank 10is sensed by a thermostat 2.6. At some predetermined low valuev oftemperature in tank 10, thermostat 26 is activated to. operate areversing solenoid S in the control circuit to turn valve so as tointerconnect tank 10 with conduit 17 as depicted in Fig. 3, which figureillustrates the cooling phase of cycle of operation.

Fluid 12 remaining in tank 10 is now circulated through region 21 bypump 14 in the direction of arrow 25d. The temperature of thecirculating fluid in tank. 10 is very low because of the precedingexpansion phaseand causes area 21 to cool. Consequently, the temperatureof area 21 drops. When thermostat 29 sensesa drop in tempera-ture inregion 21 of some desired and predetermined value, it causes motorrotation to reverse. Circulation of the cooled refrigerant 12 continuesthrough region 21 but now in the direction of arrow 25a. Thelast-mentioned reversal of motor M and thus reversal of pump operationserves to prepare the system for the compression phase next to follow.As fluid 12 continues to circulate and cool area 21, the temperature intank 10 rises. The duration of the cooling phase of the cycle continuesuntil the temperature of the circulating fluid 12 reaches a preselectedvalue in tank 10 which is sensed by thermostat 26. This causesthermostat 26 to operate the reversing mechanism S so that valve 15turns back to the position shown in Fig. 1 and thus starts the systemfor the first phase of the operation.

The refrigerant system shown herein may be operated by manual control orautomatic means. If automatic regulation is employed a conventionalregulating'circuit may be used. Consequently, the circuit depictedherein is shown schematically. The control circuit includes motor M anda conventional reversing relay responsive to thermostat swi ch 29 andincorporated in motor M for controlling the direction of motor rotationand thus the direction of pump operation. Motor M is mechanically linkedto pump 14 as shown by broken line to effect pump operation. A reversingsolenoid S is respfonsive to operation of thermostat switch 26 and ismechanically linked to valve 15 to regulate the position of same. Theforegoing units are connected to respective switches 26, 29 by wires 30.

Automatic operation will now be summarized. As noted hereinbefore,during the cooling phase, fluid 12 circulates through tank 10 and area21. At the start of this phase, the temperature in tank 10 will berelatively low, for example in the order of 38 F. or 40 R, whereas thetemperature of area 21 normally will be above a preselected value suchas 50 F. Actually, the rise of temperature in area 21 above thepreselected value of 50 F. lead to the cooling phase by triggering thesystem into the immediately preceding expansion phase. During thecooling phase, the temperature of area 21 drops as the temperature intank 10 rises. When the temperature of area 21 drops below a secondpreselected value, for example 47 F., thermostat 29 causes pump 14 toreverse to effect the flow of circulating fluid 12 in the direction ofarrow 25a. This is desirable in order to prepare the system for thesubsequent condensing phase of operation next to occur. However, thecooling phase continues with flow as depicted by arrow 25a until thetemperature in tank 10 rises to a preselected value, for example 43 F.or even 45 F., but preferably after motor M has been reversed bythermostat 29 to eflect flow depicted by arrow 25a. When thermostat 26senses the predetermined and relatively higher temperature in tank 10,the cooling phase ceases and valve 15 is reversed to couple with branch16 to initiate the compression phase. As noted hereinbefore, vessel 11is fully expanded, reservoir 23 is substantially full of fluid 12 atthis time.

The compression phase follows the pattern as described hereinbefore.During this phase, valve 20 will ultimately open to allow circulation offluid 12 through branch 18 and tank 10. The condensing phase and thuscirculation of fluid 12 will continue in this manner until a commandsignal is provided by thermostat 29. This will occur when thetemperature of area 21 finally rises above a predetermined value, suchas 50 F., and thus triggers pump reversal to effect fluid flow in thedirection of arrow 25d. Once this comes about, the expansion phasecommences and continues until thermostat 26 senses the low temperatureof 38 F. which causes valve 15 to turn and couple to conduit 17 toinitiate the cooling phase.

When the equipment is initially turnedon, the temperature in area 21normally will be higher than the 50 value, consequently, it is desirablethat thermostat 29 is manually interrupted or otherwise interrupted bythe starting switch employed to allow one compression phase of a cycleto be completed.

It should be understood that the values of predetermined and preselectedtemperatures set forth herein are merely illustrative examples todescribe system operation.

Since many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Refrigeration apparatus comprising, means containing a flowableconvective carrier, expandable and contactable means containing arefrigerant mediumvand being immersed and suspended in said carrier,means for circulating said carrier through said first-mentioned meansand into alternate conduits externally of said first-mentioned means, afirst of said conduits including avbranch for returning said carrier tosaid first-mentioned means, the second of said conduits beingoperatively associated with a region to be cooled, means for regulatingcirculation of said carrier through said first-mentioned means and saidalternate external conduits wherein, said apparatus undergoingcondensing phase of operation as said regulating means causes saidcarrier to circulate through said first conduit and through saidfirst-mentioned means at a differential amount to effect increasingpressure on said expandable and contractable means so as to contractsarne, and means for checking circulation of said carrier into saidfirst-mentioned means as said carrier ports therefrom: and into saidfirst conduit during an expansion phase of operation, said regulatingmeans causing said carrier to circulate through said first-mentionedmeans and said second conduit during the cooling phase of operation.

2. Apparatus as defined in claim 1 wherein said firstmentioned meanscomprising, a pressure type tank having first andsecond ports, saidexpandable and contractable means being a vessel in said tank, at leastone of said conduits extending externally of said tank and communicatingwith said ports and being adapted for circulating said flowable carrierexternally of said tank and back into said tank.

3. Apparatus as defined in claim 2. wherein, said tank having a thirdport, the other of said conduits communicating with said third port andalso with said first port, said first conduit including a storagereservoir for said fiowable carrier.

4. Refrigeration apparatus comprising, a tank containing a flowableconvective carrier, an expandable and contractable vessel containing arefrigerant medium and being immersed and suspended in said carrier,means for circulatingsaid carrier through said tank and into alternateconduits externally of said tank, one of said conduits including abranch for returning said carrier to said tank and the second of saidconduits being operatively associated With a region to be cooled, meansfor regulating circulation of said carrier through said tank and saidalternate external conduits wherein, said apparatus undergoingcondensing phase of operation as said regulating means causes saidcarrierto circulate through said first conduit and through said tank ata diiferential amount to cause an increasing pressure on said vessel tocontract same, and means for checking circulation of said carrier intosaid tank as said carrier ports therefrom and into said first conduitwhile said vessel is allowed to expand, said regulating means causingsaid carrier to circulate through said tank and said second conduitduring the cooling phase of operation.

5. Apparatus as defined in claim 4, said tank having first, second andthird ports, said regulating means including a two-way valvecommunicating with said first port, said first and second conduitscommunicating with said second and third ports, respectively, and bothcommunicating with said two-way valve, actuation of said valve from oneto another of two positions allows said flowable carrier to flow fromsaid tank into a respective conduit.

6. Apparatus as defined in claim 5 wherein said checking meanscomprising, a valve at said second port communicating with said firstconduit and adapted-to allow circulation of carrier through said firstconduit and said tank during the condensing phase of the cycle forcontracting said vessel and checking flow of said carrier into said tankduring the expansion phase of the cycle to permit expansion of saidvessel, said two-way valve being actuated to allow porting of saidcarrier from said tank during both the condensing and expansion phasesof the cycle.

7. Apparatus as defined in claim 6 wherein said tank having a valveresponsive to the pressure of carrier in said tank and adapted to allowthe flow of carrier therefrom when the pressure therein rises to apredetermined amount.

8. Refrigeration apparatus comprising, a tank containing a flowableconvective carrier, an expandable and contractable vessel containing arefrigerant medium and being immersed and suspended in said carrier,means for circulating said carrier through said tank and into alternateconduits externally of said tank, one of said conduits including abranch for returning said carrier to said tank and the second of saidconduits being operatively associated with a region to be cooled, meansincluding a two-way valve for regulating circulation of said carrierthrough said tank and said alternate external conduits wherein, saidapparatus undergoing a condensing phase of operation as said regulatingmeans causes said carrier to circulate through said first conduit andthrough said tank at a difierential amount to cause an increasingpressure on said vessel to contract same, and means for checkingcirculation of said carrier into said tank as said carrier portstherefrom and into said first conduit while said vessel is allowed toexpand during a succeeding phase of operation, said regulating meanscausing said carrier to circulate through said tank and said secondconduit during the cooling phase of operation.

9. Apparatus as defined in claim 8 further comprising, a reservoir forstoring an overflow of fiowable carrier and communicating with saidfirst conduit, and cooling means operatively associated with said firstconduit.

10. Apparatus as defined in claim 8 further comprising, temperatureresponsive means in said tank for activating operation of said two-wayvalve for interconnecting said tank with said second conduit for thecooling phase of the cycle, and for interconnecting said tank with saidfirst conduit during the condensing and expansion phases of said cycle.

References Cited in the file of this patent UNITED STATES PATENTS1,469,729 Myers Oct. 2, 1923 1,668,771 Kellog May 8, 1928 2,039,999Holyfield May 5, 1936 2,772,543 Berry Dec. 4, 1956

